Olfactometer

ABSTRACT

THE OLFACTOMETER INCLUDES A PERFUME SOURCE FOR HOLDING A PERFUME SAMPLE AND ONE OR MORE RAREFYING DEVICES, WITH CONNECTIONS THERETO FROM A METERED AIR SUPPLY FOR RAREFYING THE PERFUME WITH AIR, CONNECTED TO THE OUTLET SIDE OF THE PERFUME SOURCE. THE PERFUME IS DILUTED UNTIL THE PERFUME IMPRESSION THEREOF CAN THEN BE DETERMINED IN DEPENDENCE OF THE CONCENTRATION AND THE THRESHOLD VALUE. THE PERFUME SOURCE AND THE OR EACH RAREFYING DEVICE ARE INTERCONNECTED BY CAPILLARY TUBES TO FORM A SINGLE COMBINATION AND THIS COMBINATION IS SO CONNECTED TO THE OLFACTOMETER CASING THAT ALL OR THE VARIOUS SECTIONS THERE-   OF CAN BE REMOVED WITH EASE AND REPLACED BY UNCONTAMINATED SECTIONS SO THAT A NEW PERFUME CAN BE TESTED IN THE KNOWLEDGE THAT THERE WILL BE NO RESIDUAL PERFUMES TO CONTAMINATE IT.

1971 R. RANDEBROCK ET 3,618,35

OLFACTOMETER 2 Shcets-f5heut 1 Filed Aug. 1, 1969 Nov. 9, 1971 R RANDEBmCK ET AL 3,618,359

OLFACTOMETER Filed Aug. 1, 1969 2 Sheets-Sheet 2 3,618,359 OLFACTOMETER Rudolf Randebrock, 32 Dusterntwiete, 2 Garstedt, Bezirk,

Hamburg, Germany, and Otto Neese, Hamburg, Germany; said Neese assignor to said Randebrock Filed Aug. 1, 1969, Ser. No. 846,700 Claims priority, application Germany, Aug. 6, 1968, P 17 98 003.9 Int. Cl. G01n 31/00 US. Cl. 73--23 6 Claims ABSTRACT OF THE DISCLOSURE The olfactometer includes a perfume source for holding a perfume sample and one or more rarefying devices, with connections thereto from a metered air supply for rarefying the perfume with air, connected to the outlet side of the perfume source. The perfume is diluted until the perfume impression thereof can then be determined in dependence of the concentration and the threshold value. The perfume source and the or each rarefying device are interconnected by capillary tubes to form a single combination and this combination is so connected to the olfactometer casing that all or the various sections thereof can be removed with ease and replaced by uncontaminated sections so that a new perfume can be tested in the knowledge that there will be no residual perfumes to contaminate it.

This invention relates to an olfactometer, which is an apparatus for the regulation of definite smell concentrations, and it is possible with its help to compare smells with one another and to ascertain possible smell thresholds.

BACKGROUND OF THE INVENTION O-lfactometers are known in several different forms, by the use of which a perfumer can determine the smell impression in relation to the concentration of the perfume and ascertain the threshold value.

Olfactometers have, for example, been developed in which, starting with a determined perfume, purified air is added in predetermined quantities, so that the mixture is once or several times rarefied and finally tested by the nose of the perfumer. These known arrangements suffer from the disadvantage of a considerably complicated construction and suffer furthermore from the disadvantage that a multiplicity of tubes is provided in which each particular perfume is rarefied with the introduced air. If the apparatus is then to be used with another perfume it is diificult, if not impossible, satisfactorily to purge such a complicated device so that for the new examination no residual perfumes remain in the tube portions of the olfactometer, so that a false result from the new examination is quite probable.

SUMMARY OF THE INVENTION The invention has as its object to provide an olfactometer which can be changed for use with one perfume quickly to another perfume, without substantial problems of removing residual perfume from the apparatus. It is also an object of the invention to produce an olfactometer in which those parts which contain the perfumes can be simply exchanged.

A further object of the invention is to provide an olfactometer which is of simple construction in which the constructional parts require little space and the indi vidual values to be read off are easily visible or adjustable.

Accordingly this invention provides an olfactometer comprising a perfume source for holding a perfume sample, one or more rarefying devices for rarefying the "United States Patent O Patented Nov. 9, 1971 perfume with air, connected to the outlet side of the perfume source, a discharge pipeline for removing unwanted perfume-air mixture, and an outlet portion for the perfume-air mixture for establishing the perfume impression in dependence of the concentration and the threshold value, the perfume source and the or each rarefying device being interconnected by capillary tubes to form a combination which is connected releasably to the olfactometer casing.

Desirably, connecting pipelines will lead out from the casing of the olfactometer, so as to be connectable and separable from the combination in a simple manner such as by rubber hosing. It is preferred that the parts of the combination will be formed from glass or a similar material.

The perfume source will desirably be capable of holding a perfume tampon, and the capillary tube above this perfume source provides a reduced through-flow of the perfume to the rarefying device into which a feed pipeline for air or another gas and the discharge pipeline for the unwanted perfume-air mixture is provided. Also a pipeline should be provided which leads to a measuring device, for example a manometer, by means of which the pressure of the mixture column in the combination is measurable and adjustable.

If it is desired to obtain further rarefaction of the perfume concentration, a multiplicity of rarefying devices, preferably releasably connected with one another, may be provided. Each will, of course, have a capillary tube as well as a supply source for air or another gas and a discharge pipeline for unwanted perfume mixture.

The parts of the combination are desirably each provided with a widened portion at the lower end for interconnection with correspondingly narrowed portions at the upper ends of the parts of the combination to provide a secure seal. By forming the various parts of the combination, as far as possible, in an identical manner, these parts are then directly interchangeable. These parts can, with advantage, be formed each from one piece of glass tubing with connecting pipelines integral therewith.

It is greatly preferred that, in the feed pipelines for air or gas to the perfume source and the rarefying devices, appropriate regulating devices for the quantity of air leading thereto should be provided. Also it is desirable that pressure regulators, by means of which the pressure of the air led to the perfume source or rarefying devices is kept constant be provided together with a device for purifying the air so supplied.

The invention has the particular advantage that, in addition to the simplicity of the construction of the olfactometer parts, after each perfume measurement, the part or parts of the combination can be simply separated from the pipelines which lead out from the olfactometer casing and removed so that for the measurement of a new perfume new purged parts can be inserted. This enables a far larger number of perfume measurements to be undertaken in a certain time compared with conventional devices and there is the further advantage that an absolute guarantee is given that in the new measurement to be undertaken, no residual perfume of an earlier measurement has remained.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully understood, a preferred embodiment thereof will now be described by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic circuit diagram of an olfactometer constructed in accordance with the invention showing removable parts thereof; and

FIG. 2 is a schematic circuit diagram of an additional part for a larger measuring range which can be connected into the circuit shown in FIG. 1.

3 DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 ShOWs a pump 1, such as a diaphragm pump, by means of which air is sucked in through a pipeline 2 from an activated carbon tower 3 into a device 52 for measuring and maintaining constant the atmospheric humidity. The compressed air from the pump 1 is led through a pipeline 4 to a needle valve 5 (represented schematically), which is connected to a U-tube-manometer 6 leading to a pressure stabilizer device 7 whereby the pressure of the air is kept constant. From the pipeline 4 a branch 8 leads to the pressure stabilizer 7, which is provided with two push-button valves 9 and 10. The compressed air can be discharged through the push-button valve 9. Beyond the needle valve 5, in the pipeline 11 which leads to the pressure stabilizer 7, there is provided a branch 12 which leads to a double T-piece, in the arms 13 and 14 of which are arranged capillary tubes 15, 16 respectively. Beyond the capillary tubes 15, 16 is a threeway cock 17, by means of which a quantity of air, determined by the thin diameter and length of the capillary tubes, may be conducted from one of the two capillary tubes 15, 16 respectively through a pipeline 18 to the olfactory tube combination (to be described in detail below and generally designated 19), which consists of the individual parts 23, 29 and 38.

If a larger quantity of air should be required after closmg the needle valve 5, a cock or valve 20 connected to the air pipeline 4 can be opened to allow air to be led through a flow meter (rotameter) 21, and through a pipeline 22 to the pipeline 18 and thence to the olfactory tube combination 19.

A further branch 23 leads from the pipeline 4 through a flow meter 24 and a pipeline 25 into the interior of the olfactory tube combination 19.

The olfactory tube combination will now be described in detail. The main section thereof comprises a glass tube 26 which extends downwardly at 27 and is capable of being affixed on a conically tapering part 28 connected to inlet pipe 18. In the lower part of the glass tube 26 is a space 29 for receiving a perfume-enriched tampon, a glass frit or the like. This space is surrounded by a sleeve for keeping the temperature constant. Above the perfume tampon space 29 there is provided a capillary tube 30 by means of which perfumes can pass through into the space 31 therebeyond. In this part of the olfactory tube combination 19 the feed pipeline 25 for compressed air from flow meter 24 terminates at end 32. Furthermore, from this space 31, a pipeline 33 is led out to a measuring apparatus, in the form of an inclined tube manometer 34, which is arranged on the front wall of the olfactometer casing and from which the regulated excess pressure can be read off. The pipeline 33 is further led to the free arm of the U-tube-manometer 6 in order to balance the pressure on the capillary tube passages 15, 16. Into the space 31 of the tube 26 is also led a delivery pipeline 35 which is provided with a control valve denoted by 36, by the regulation of which the excess pressure, as read off on the inclined tube manometer measuring tube 34, can be regulated.

By means of this construction it is therefore possible both to regulate the air pressure exactly and to effect a desired rarefaction in the perfumes flowing from the space 29 through the capillary tube 30 into the space 31. The exact amount of perfume which enters space 31 is of course related to the volume of the capillary tube 15 or 16 and any air let in through the valve 20.

The upper end of the tube 26 is tapered at 37 and receives a further constructional part 38 of the olfactory tube combination 19. It is possible to release a specified quantity of perfume-air through a capillary tube 39, provided in the upper constructional part 83, by virtue of the air pressure regulated in the space 31. The mixture in part 38 can be rarefied again in a controllable manner and to this end a feed pipeline tube 40 is provided which is connected through a fiow meter 41 and a pipeline 42 to a T pump 44, such as a diaphragm pump. This pump 44 is in turn connected through the apparatus for regulating the atmospheric humidity 52 to the activated carbon tower 3. Of course it is alternatively possible to discharge this compressed air by means of the pump 1.

At the upper end of the tube 38 can be established, by a perfumer, the smell impression, dependent upon the concentration and threshold values ascertained.

Should a further degree of rarefaction be desired, an additional tube 45 (shown in FIG. 2) can be inserted between the tubes 26 and 38. This tube contains a capillary tube 46 and the pressure therein is measured on a pressure gauge in the form of a further inclined tube manometer from a second olfactometer. Connections are provided respectively for air intake at 47, to the inclined tube manometer at 48 and for spent air at 49. All these connections are accordingly connected to the second olfactometer.

A connection for compensating the pressure difference is also provided which is counterconnected to the inclined tube manometer 34 of FIG. 1. The tube 45 will be mounted upon tube 26 and as previously the tube 38 with its corresponding connections will be set on top. If it is desired to rarefy the perfume-air mixture still further, then several tubes 45 can be mounted one upon the other between tubes 26 and 38. The connections to the pipelines 18, 32, 33, 35, 40, 47, 48, 49 and 50 can be provided by means of hoses or the like, led out from the casing of the olfactometer, so that connection can easily be made or disconnected.

Once the examination of a perfume sample has been completed, it is merely necessary to separate the individual connections, take off the olfactory tube combination, consisting of the tube 19 alone or with the addition of a multiplicity of tubes 45 arranged one upon the other, and to substitute another olfactory tube or another olfactory tube combination. The examination of another perfume can then be undertaken.

We claim:

1. An olfactometer comprising:

a first tube having a widened portion at one end and a narrower portion at the other end for holding an odoriferous material having at least a first capillary inlet and a first capillary outlet,

means connected to said first inlet for supplying a gas to said first tube at a given rate so that the fumes from said material mix with the gas supplied,

means for varying said given rate said gas is supplied to said first tube,

a second tube having a widened portion at one end and a narrower portion at the other end with the narrow portion of one tube fitting into the widened portion of the other tube, having a first inlet connected to said first outlet for receiving mixed gas and fumes from said first tube, having a second inlet, and having an outlet,

means connected to said second inlet for supplying gas to said second tube at a predetermined rate so that the mixture of gas and fumes entering said second tube from said first tube is further rarified a predetermined amount, and

means for varying said predetermined rate gas is supplied to said second tube.

2. An olfactometer as in claim 1 wherein said second tube includes a pump for supplying gas at a pressure above atmospheric pressure and a fiowmeter connecting said pump to said second chamber means.

3. An olfactometer as in claim 1 wherein said first and second chamber means are glass tubes removably connected together.

4. An olfactometer as in claim 1 further including,

a third tube having an inlet connected to said outlet of said second tube for receiving mixed gas and fumes from said second tube, having a third inlet, and having an outlet, and

means connected to said third inlet for supplying gas to said third tube at a predetermined rate so that the mixture of gas and fumes entering said third tube from said first tube is further rarefied a predetermined amount, and wherein said second outlet of said second tube is a capillary.

5. An olfactometer comprising:

a first chamber means for holding an odoriferous material having at least a first capillary inlet and a first capillary outlet,

means connected to said first inlet for supplying a gas to said first chamber means at a given rate so that the fumes from said material mix with the gas supplied, including a pump for supplying gas at a pressure above atmospheric pressure, a pair of capillary tubes connected in a T-piece having an inlet and outlet, a needle valve connecting the inlet of said pair of tubes to said pump and a three way cock connecting the outlet of said pair of tubes to said first chamber means,

a second chamber means having a first inlet connected to said first outlet for receiving mixed gas and fumes from said first chamber means, having a second inlet, and having an outlet,

means for varying said given rate said gas is supplied to said first chamber means,

means connected to said second inlet for supplying gas to said second chamber means at a predetermined rate so that the mixture of gas and fumes entering said second chamber means from said first chamber means is further rarefied a predetermined amount, and

means for varying said predetermined rate gas is supplied to said second chamber means.

6. An olfactometer as in claim 5 wherein said first chamber supplying means further includes means for 10 manually adjusting the pressure on both sides of said pair of tubes so as to adjust the rate of flow of said gas to said first chamber means.

References Cited OTHER REFERENCES Moncrieff: The Chemical Senses 1948 at p. 80.

RICHARD C. QUEISSER, Primary Examiner 25 E. J. KOCH, Assistant Examiner 

